Alien Invaders: A Guide to Non-Native Species of the Britisher Isles by Jacob Cartwright and Nick Jordan (Book Works, £6.50)

Cartwright and Jordan are artists, who describe this little hardback as a "cross-pollination of fact and fiction". The reader may find it hard to separate the strands. Can it really be true that between 30,000 and 50,000 road accidents each year in the UK involve deer? According to a website called deercollisions.co.uk, it is. On the other hand, I do not think that mitten crabs, plaguing fishermen, steal a bait called "Urk". A stew of grey squirrel, we read, was known in the US South as "limb chicken", and was a favourite of the young Elvis Presley. The Princess of Wales used to take Princes William and Harry to scatter nuts for the grey squirrels in the garden of Kensington Palace; after her death, five dozen squirrels, allegedly the victims of vengeful royal gardeners, were found drowned in the palace lake.

Alien Invaders has entries on 10 species that have become ruthlessly efficient at adapting to their new home in the UK. There are silhouettes in the text - of Elvis, for example - and slyly humorous colour plates. The combination of fact, bizarre anecdote and invention gives to the species a patina of myth. Cartwright and Jordan may have human analogies in mind.

Line of Flight by John McAllister (Bluechrome, £9.99)

The ceasefire in Northern Ireland offers little protection to the characters in John McAllister's debut thriller. They get shot, or blown up, or incinerated; one has his throat ripped out by doberman pinschers. The new political climate influences them only to form cynical alliances with their former enemies and to assassinate their former allies.

McAllister's protagonist, portrayed in unsqueamish but heroic terms, is a Protestant hardman called Jimmy Terrance. Jimmy's son is dating a Catholic girl, Roisin - or, as Jimmy's wife Eleanor prefers to describe her, "that whore of Rome". A bigger problem than this religious sensitivity, however, is Roisin's apparent involvement in a dispute that is keeping hitmen busy all over Belfast. The plot races to a lurid climax at a building site in London, where McAllister's villains - only slightly more psychopathic than his other characters - plan a spectacular act of terrorism to mark the state opening of parliament. It is not always easy to work out what is going on in Line of Flight: this is a hard world, in which alliances are obscure, motivations are opaque and dialogue is functional. McAllister's laconic narrative, albeit infused with elements of grand guignol, carries a strong charge of authenticity.